Colchester master cross-feed problem

Hello again "K",

I see that someone has responded to your thread regarding this issue. I don't want to steal his thunder, so I will tell you how I removed the apron on mine.

First off, do you have a manual for your lathe and a parts list and diagramatical breakdown? If you do, it will be so much easier for you.

Secondly, on my particular model, the tail-stock end bearing block, for the lead and feed screws are part of the main bed casting. Because of this, there is a little more work involved. If your bearing block on your lathe is a separate part, the job will be less involved.

If your bearing block is an integral part of the main casting, you will have to separate the lead and feed screws from the gear box, release the tail-end collar grub screw on the feed shaft and slide both shafts through the bearing block about halfway. They should be supported with blocking or whatever you can come up with, so that they don't bind in the bearing block and damage the bearings.

On my lathe, I didn't have to remove the saddle, cross-slide, nor the compound slide to remove the apron.

The first thing to do is to remove the lower gearbox (threading gearbox) cover.

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Sorry for the fuzzy pic. This pic shows the left driving shaft gear. There is a retaining collar with a circlip holding the collar. Remove the circlip and slide the collar to the left. This would be a good time to take a digital picture for your own reference with this cluster of gears and collars. It's not a real complicated arrangement, but I did.

The next two pics show the leadscrew gear and the driving gear coming into mesh. To do so, simply roll the chuck around and manipulate the "metric/neutral/imperial" lever to engage the slots. This is to allow a little more room for the next step.

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Now, remove the grub screw from the locking collar at the far right of the gearbox...

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Then, unscew one collar at a time until both are entirely clear of the threads on the leadscrew. It may be neccesary to slide the leadscrew out of the gearbox a little to gain enough space to do so. Now, the leadscrew should be free to slide out of the gearbox. Once the leadscrew was clear of the gearbox and supported, I slid a bar through the gears and collars and pulled the whole lot from the gearbox to keep the proper sequence of parts.

Now slide the leadscrew clear of the gearbox and support it.

Next is the feed shaft. There is a pin that binds the feedshaft coupling to the feed shaft. The pin is located outside of the gearbox. Drive this pin out and then slide the feed shaft free of the apron and support it.

In this pic, you can see two locking collars on the outside of the gearbox for the leadscrew. DO NOT fiddle with these locking collars. It is not necessary.... It's been some time since I removed the apron and can't recollect exactly how got the leadscrew free of the apron. I think that I had to manipulate the leadscrew at the same time that I removed the apron.

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Next, are 4 capscrews to remove on the saddle which will detach the apron from the saddle in its entirety. It's a little heavy, but not overly so. It's not a bad idea to have some blocking beneath it to catch it in case it falls.

Now it should be fairly straightforward from here. I'll have to go have a boo at what I wrote and make sure that it makes sense. Feel free to ask any questions. I was a little intimidated when I first did this, but it's really just one part at a time.

Oops... pic 3 and 4 should be reversed...

Best regards... :)

Brian

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Hey Brian, I've found that no matter how clean we might think our apron is, the Colchester has its own opinion on that. When I bought mine the cross feed wouldn't work so I tore it down like you did (I didn't have any drawings). Once I got it all torn apart I didn't see anything either. So I just cleaned everything, and reassembled the whole damn thing. Now it works fine. I still get mad thinking about it, I hate not finding out what was wrong.
 
see two locking collars on the outside of the gearbox for the leadscrew. DO NOT fiddle with these locking collars. It is not necessary.... It's been some time since I removed the apron and can't recollect exactly how got the leadscrew free of the apron. I think that I had to manipulate the lead screw at the same time that I removed the apron.

IMGP0028800x600_zps1cd300ab.jpg

You have to remove these locking collars to remove the Key it is a keyed bush beside the lock collars the key then goes through bearing and into the lead screw you cannot remove the lead screw without doing so there is also a threaded collar inside the box with a grub screw and lead plug in it this has to be undone remove the circlip from it's seat remove gear selector lever drive out roll pin pull lever out lift out selector once thats done engage half nut and wind back the saddle (towards tailstock) this will drag the lead screw out removing the circlip washer and dog clutch gears as the shaft comes out placing parts on shelf in order. Wind the leadscrew only half way release the halfnut wind the saddle (towards head stock) till it's clear off the lead screw
The drive shaft undo grub screw in collar at tailstock end then drive out roll pin as in picture above this shaft should just pull out easy only till its clear of the saddle
to remove the apron support it on the chip tray remove the four cap screws from the saddle drop the apron clear easy slide the lead screw back in and the drive shaft for support and protection
Reassembly is just the reverse the locking collars are not done up dead tight just to the point that you feel the lead screw starts to tighten loose is ok at this point once it's all put back together run it and check the backlash adjust
accordingly
hope this helps some one you probably have it all sussed by now
cheers Kiwi
 
Hi Kiwi, I too am from the land right under. I hope you still visit these boards because I'm currently in the process of a full tear down and rebuild of this model Colchester and could do with some help. At the moment I'm struggling with removing the tumbler handle shown bottom of your photo above, Is there some kind of shear pin inside the bushing? I noticed a small grub screw on the front.
 
Hi Ropata on brian's #11 post on this page you can see the end of the roll pin stuff a rag under it to catch it if you knock it too far just take a pin punch and tap it out the lever will then pull out then the dog clutch slide will lift out I suggest that taking photos at every stage of the strip down they sure help on re assembly month's latter
 
Yeah thanks, I'm looking to pull the lever apart too so have you had the lever apart from the slide that goes into the gearbox?
 
Good morning Brian,stopped by to catch up on what's going on.Read about your problem then solving it which is fantastic and I learned by looking at your pics that I am missing a gear for going from metric/imperial threading.Anyway nothing better than fixing these lathes problems,but once fix correctly they will last the next owners lifetime.Na I having to take a leave of absence from my lathe due to work at work and picking up work at the homestead which I posted over in the Doall section.For now not much time for myself but that's OK
 
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